There are a lot of really easy ways to rationalize not testing your code, and I’m probably guilty of saying each of them at one point or another. For some engineers, I think the reluctance to embrace unit testing is basically just FUD. Like so many other things, testing seems scary if you haven’t done it before.

But it’s also really difficult to fully understand the benefits of testing unless you’ve worked on a project that has good tests. So it’s easy to see why?—?without fully understanding the upside?—?many developers regard unit testing as an unnecessary step.

He goes through several of the common excuses for not writing unit tests and debunks them one at a time. He also includes a brief section at the end of the post with a recommendation on how to get started testing...essentially "just do it".